onClick從editText獲取文本時崩潰

當執行我的onClick方法來顯示editText中的文本的按鈕時，我的應用程序由於NullPointerException而崩潰，我找不到原因。當我完全刪除對editText的引用時，一切正常。我究竟做錯了什麼？onClick從editText獲取文本時崩潰

public void onClick(View v) { 
    EditText editText1 = (EditText) v.findViewById (R.id.editText1); 

    switch (v.getId()) {  
    //add entry to the List 
     case R.id.button1: 

      Toast.makeText(getActivity(), "Clicked on add button" + " CRN: " + editText1.getText().toString(), Toast.LENGTH_LONG).show(); 

     case R.id.button2: 
      Toast.makeText(getActivity(), "Clicked on delete button", Toast.LENGTH_LONG).show(); 


    } 
    }

錯誤的問題：

01-12 19:32:57.726: E/AndroidRuntime(23216): FATAL EXCEPTION: main 
01-12 19:32:57.726: E/AndroidRuntime(23216): java.lang.NullPointerException 
01-12 19:32:57.726: E/AndroidRuntime(23216): at com.example.project.ClassesFragment.onClick(ClassesFragment.java:85) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at android.view.View.performClick(View.java:4475) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at android.view.View$PerformClick.run(View.java:18786) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at android.os.Handler.handleCallback(Handler.java:730) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at android.os.Handler.dispatchMessage(Handler.java:92) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at android.os.Looper.loop(Looper.java:137) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at android.app.ActivityThread.main(ActivityThread.java:5419) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at java.lang.reflect.Method.invokeNative(Native Method) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at java.lang.reflect.Method.invoke(Method.java:525) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:115) 
01-12 19:32:57.726: E/AndroidRuntime(23216): at dalvik.system.NativeStart.main(Native Method) 
01-12 19:33:12.040: I/Process(23216): Sending signal. PID: 23216 SIG: 9

來源

2014-01-13 Chase Kelly-Reif

你的情況下的值，可能爲空。你有沒有在onClick之前正確實例化它們？ – SoulRayder

你能告訴我們你的onClick方法嗎？ – Raghunandan

在每種情況下使用break並且空指針是因爲你可能會給出錯誤的ID – jyomin

如果是在片段佈局然後在onCreateView

EditText ediText1; 
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
     Bundle savedInstanceState) { 
    // TODO Auto-generated method stub 
    View v = inflater.inflate(R.layout.fragmentlayout, container, false); 
       editText1 = (EditText) v.findViewById (R.id.editText1); 
    return v; 
}

或

你可能會引用錯誤的ID。

你缺少休息

case R.id.button1: 

     Toast.makeText(getActivity(), "Clicked on add button" + " CRN: " + editText1.getText().toString(), Toast.LENGTH_LONG).show(); 

break; // missing

來源

2014-01-13 03:42:01 Raghunandan

onCreateView隨着添加中斷更改修復了問題。謝謝！ –

@Chase很樂意幫忙。 – Raghunandan

public void onClick(View v) { 
//defining edit text 
EditText editText1 = (EditText) findViewById (R.id.editText1); 

switch (v.getId()) {  
//add entry to the List 
    case R.id.button1: 
     Toast.makeText(getActivity(), "Clicked on add button" + " CRN: " + editText1.getText().toString(), Toast.LENGTH_LONG).show(); 
     //stop button event 
     break; 
    case R.id.button2: 
     Toast.makeText(getActivity(), "Clicked on delete button", Toast.LENGTH_LONG).show(); 
     //stop button event 
     break; 

} 
}

來源

2014-01-13 03:57:58

onClick從editText獲取文本時崩潰

回答

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